Problem with email delivery new install - ubuntu 7.10

I have followed the setup for the perfect setup. And all went quite smooth. Have been adding domains and email addresses. And was about to switch over my server. Then I tried to test email delivery. And as much as all seems to go without problems in the log. The mail doesnt get delivered (at least not in the right place.

Just FYI - right now i have an old linux server running with a cyrus setup - that I want to migrate to the ISPconfig install.
The websites are already all working - and creating email addresses seemed to work as well.

I'm running ISPconfig version: 2.2.18
I did turn on Maildir in the settings of ISPconfig - but i only did after creating the accounts.

I can't see where it's going wrong. Some of the mails i tried are delivered in /var/mail/xxx
But can't find all of them there - and there are no delivery errors.

checked the hosts file. Both localhost and the ipnr are linked to mail.q#####.com, localhost.q#####.com, localhost

and hostname returns mail.q#####.com,
hostname -f returns localhost

Still the log now complains that the host or domain is not found. Name service error for name=mail.q#####.com type=MX: host not found)

I should add that at this moment the machine is not connected to the internet - as that domain on the internet would still point to my old server. But i think that in this case the hosts file should be sufficient

just a small question - right now i have in the hosts file the 127.0.0.1 - and the ip of my internal network linked to the ISPconfig host. When i put it online - i guess i should also put the external ipnumber of the site there.